Wood Stork

Wood Stork in Flight The largest wading bird and the only stork to breed in the United States, the wood stork (Mycteria americana) is placed in the Order Ciconiiformes and the Family Ciconiidae. The bird's genus name derives from the Greek word for "nose," and the species name refers to it being found almost exclusively in the United States, Mexico, and Cuba. Most populations are found in southern Florida, but their ranges have been observed shifting northward in recent decades; in Alabama, wood storks have been documented near Montgomery, in the Tombigbee River, at Eufaula National Wildlife Refuge, and in western Alabama in Hale, Marengo, and Perry Counties, where they are considered regular visitors in the summer and early fall.

Wood storks stand at about 34 to 45 inches (86-115 centimeters) tall and have wingspans of 60 to 65 inches (152-165 centimeters). The most distinguishing feature of a mature wood stork is its long and sizeable black beak, which tapers to a down-curved point. Wood storks have white body feathers and black wing edges. Juveniles have bills that are more yellowish than those of adults, as well as some gray feathers on their heads and necks.

Like many members of the Ciconiidae, or stork family, wood storks capture food using their bill. They possess some of the fastest reflexes among known vertebrates, snapping their bill shut at around 25 milliseconds as they probe water up to 20 inches deep for small fish. This ability to hunt by feel allows them to feed day or night in freshwater marshes, swamps, narrow tidal creeks, and flooded tidal pools. They rely on the alternating flooding and drying of these areas to both increase and concentrate the fish they consume. During floods, the fish have the space and resources to reproduce, and during dry periods, the fish become concentrated in smaller pools and are thus easier to find and catch.

Wood Stork and Young Wood storks commonly nest in groups (called rookeries) within cypress or mangrove swamps. But unlike other avian species, which typically prefer to nest near their food sources, wood storks will travel up to 80 miles from their nests to feeding areas. Their large wings allow them to rise high into the sky on thermals, or columns of hot air. Thermals form later in the day as the sun heats the earth's surface, so wood storks may delay feeding until thermals form. The distance a stork will fly in order to feed its young depends on the food availability in the area.

Females lay between two and five eggs, and most successful nests fledge two young. Both female and male storks sit on the eggs in shifts. After hatching, nestlings stay in the nest for seven to eight weeks and are reliant on their parents for food until they are nine to ten weeks old. Fledglings then leave the rookery and live away from the group until they reach maturity at three to four years old. They are considered to primarily nest in southern Florida, Mexico, and Central America, rarely breeding in Alabama.

They are not considered true migrants, but they frequently move around their typical region based on the availability of food resources. In Alabama, they can be observed in Hale, Marengo, and Perry Counties in the summer and early fall near suitable water sources. Also during this time period, they can be found in the western Inland Coastal Plain near the Tombigbee River, a popular place for birdwatchers to view them.

Juvenile Wood Storks Wood storks are listed as "threatened" and of the highest conservation concern by the U.S. Fish and Wildlife Service. In the 1930s, there were an estimated 20,000 breeding pairs of wood storks in the United States. For several decades afterward, there was a steep decline in their populations, with only 5,000 pairs leading into the 1980s. According to the U.S Fish and Wildlife Service, this decline was largely the result of decreasing food availability and loss of nesting habitat. Breeding colonies require high concentrations of prey populations, as the average nesting pair and their young require more than 400 pounds of fish during the breeding season. Declines of wetland areas and their food resources led this species to be listed as endangered in 1984. Since that time, wood stork populations have been observed to increase and expand their ranges, resulting in their status being changed to "threatened" in 2014. Conservation of the wood stork is mostly centered on water-level management near their nesting areas. Wildlife managers believe that flooding areas around rookeries may be crucial to stimulate nesting and prevent predators from consuming nestlings. Conservation officials hope that wood stork populations will eventually make a full recovery with continued preservation of wetland areas and increasing awareness of the numerous species that rely on them.

Further Reading

  • Bryan, A. Lawrence, et al. "Satellite Tracking Large-Scale Movements of Wood Storks Captured in the Gulf Coast Region." Waterbirds 31 (Spring 2008): 35–41.
  • Ogden, John C., Donald A. McCrimmon, G. Thomas Bancroft, and Barbara W. Patty. 1987. "Breeding Populations of the Wood Stork in the Southeastern United States." The Condor 89 (November 1987): 752.

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